Constraint-Directed Backtracking

نویسندگان

  • Wanlin Pang
  • Scott D. Goodwin
چکیده

We propose a new backtracking algorithm called constraint-directed backtracking (CDBT) for solving general constraint-satisfaction problems (CSPs). CDBT and the naive backtracking (BT) share a similar style of instantiating and re-instantiating variables. They diier in that CDBT searches for an assignment to variables in a variable set from the given constraint posed on that variable set and appends it to an existing partial solution, whereas BT searches for an assignment of one variable from its domain. CDBT has a more limited search space and it actually visits fewer nodes than BT. The similarity between CDBT and BT enables CDBT to be incorporated with other tree search techniques such as backjumping or forward checking and consistency techniques such as the !-consistency algorithm to improve its performance further.

برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید

ثبت نام

اگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید

منابع مشابه

Constraint-Directed Backtracking Algorithm for Constraint-Satisfaction Problems

We propose a new backtracking method called constraint-directed backtracking (CDBT) for solving constraint-satisfaction problems (CSPs). CDBT and chronological back-tracking (BT) share a similar style of instantiating variables (forward) and re-instantiating variables (backward). They diier in that CDBT searches instantiations of variables in a variable set from a given constraint posed on that...

متن کامل

Intelligent search strategies based on adaptive Constraint Handling Rules

The most advanced implementation of adaptive constraint processing with Constraint Handling Rules (CHR) allows the application of intelligent search strategies to solve Constraint Satisfaction Problems (CSP). This presentation compares an improved version of conflict-directed backjumping and two variants of dynamic backtracking with respect to chronological backtracking on some of the AIM insta...

متن کامل

Formalizing Dependency Directed Backtracking and Explanation Based Learning in Refinement Search

The ideas of dependency directed backtracking (DDB) and explanation based learning (EBL) have developed independently in constraint satisfaction, planning and problem solving communities. In this paper, I formalize and unify these ideas under the task-independent framework of refinement search, which can model the search strategies used in both planning and constraint satisfaction. I show that ...

متن کامل

Hybrid Algorithms for the Constraint Satisfaction Problem

It might be said that there are five basic tree search algorithms for the constraint satisfaction problem (csp), namely, naive backtracking (BT), backjumping (BJ), conflict-directed backjumping (CBJ), backmarking (BM), and forward checking (FC). In broad terms, BT, BJ, and CBJ describe different styles of backward move (backtracking), whereas BT, BM, and FC describe different styles of forward ...

متن کامل

A Theoretical Evaluation of Selected Backtracking Algorithms

In recent years, many new backtracking algorithms for solving constraint satisfaction problems have been proposed. The algorithms are usually evaluated by empirical testing. This method, however, has its limitations. Our paper adopts a different, purely theoretical approach, which is based on characterizations of the sets of search tree nodes visited by the backtracking algorithms. A notion of ...

متن کامل

ذخیره در منابع من


  با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید

برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید

ثبت نام

اگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید

عنوان ژورنال:

دوره   شماره 

صفحات  -

تاریخ انتشار 1997